The invention concerns a process for recycling plastics, and an arrangement for implementing such a process.
Processes of a similar kind have long been known in prior art. Thus, it is known that recyclable plastic materials can be first reprocessed in a cutter compactor at an increased temperature—by applying a vacuum if practicable—and subsequently melted in an extruder, that the melt is then filtered, degassed and finally, for example, granulated. Arrangements for implementing such processes are known, for example, from EP 123 771 B, EP 390 873 B or AT 396 900 B.
Furthermore, numerous processes and arrangements exist to optimize the different steps such as degassing the melt. For example, the formation of a pressureless zone upstream of the degassing openings can be provided to ensure the reliable degassing of the plastic material. Furthermore, some arrangements exist with which it is attempted to keep the migration route of the gas bubbles embedded in the plastic as short as possible to allow the gas bubbles to exit the melt before it is conveyed past the last degassing opening. They are, in particular, arrangements which reshape the plastic material into a tubular form.
There also exist numerous embodiments of various melt filter to remove solid impurities and/or non-molten residual polymer.
These all have the prime purpose of enhancing the quality of the final product.